1. Field of the Invention
The present invention relates to an actinic-ray- or radiation-sensitive resin composition that can find appropriate application in a semiconductor production process for an IC or the like, a circuit board production process for a liquid crystal, a thermal head or the like and other photofabrication lithography processes. The present invention also relates to an actinic-ray- or radiation-sensitive film formed from the composition and a pattern forming method using the composition. Further, the present invention relates to a process for manufacturing an electronic device and an electronic device.
2. Description of the Related Art
Since the development of the resist for a KrF excimer laser (248 nm), a pattern forming method in which chemical amplification is utilized has been employed in semiconductor lithography.
Shortening of the wavelength of exposure light sources and realization of high numerical apertures (high NA) for projector lenses have been promoted in order to cope with the miniaturization of semiconductor elements. To now, an exposure unit comprising an ArF excimer laser of 193 nm wavelength as a light source has been developed. A method (known as a liquid-immersion method) in which the space between a projector lens and a sample is filled with a liquid of high refractive index (hereinafter also referred to as an “immersion liquid”) has been proposed as a technology for enhancing the resolving power. Moreover, an EUV lithography in which the exposure is carried out using an ultraviolet of further shorter wavelength (13.5 nm) has been proposed.
However, the current situation is that it is extremely difficult to discover an appropriate combination of resist composition, developer, rinse liquid, etc., required for the formation of a pattern realizing comprehensively excellent performance, so that there is a demand for further enhancement.
In the above-mentioned current situation, a variety of compounds have been developed as photoacid generators that constitute a major component of the chemically amplified resist composition. For example, sulfonium salt photoacid generators are described in patent references 1 to 4.
In recent years, methods of forming a pattern with a developer comprising an organic solvent are being developed (see, for example, patent references 5 to 12). For example, patent references 6 to 11 describe methods of forming a pattern, each comprising the operation of developing a resist composition, in which a resin containing a repeating unit containing a group that is configured to decompose when acted on by an acid to thereby produce a polar group is incorporated, with a developer comprising an organic solvent.